Bovine serum albumin (bsa)

2-Aminoethyl
methacrylate (AEMA, 98%, Macklin Inc) and [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium
hydroxide (SBMA, 99%, J&K Scientific) were employed as monomers
to synthesize the zwitterionic copolymer P[SBMA-co-AEMA] as reported by Han et al.,^{14 (link)} and
the detailed process was illustrated in the Supporting Information (S1). The M_n and M_w of the resultant zwitterionic copolymer were
3216 and 4237 Da, respectively, which were measured by the gel permeation
chromatography experiments at room temperature with DI water as the
mobile phase and polymethyl methacrylate as the standard. 1,3,5-Benzenetricarbonyl
trichloride (TMC, 98%, J&K Scientific), piperazine (PIP, >99%,
J&K Scientific), and polyethylene glycols (PEG, 99%) with different
molecular weights between 200 and 800 g/mol were purchased from Sigma-Aldrich
(China). 2,2′-Azoisobutyronitrile (AIBN, 99%), dimethyl sulfoxide
(DMSO, 99.5%), n-hexane (99.5%), sodium hydroxide
(NaOH, 99.9%), sodium chloride (NaCl, 99.9%), phosphate-buffered saline
(PBS, pH 7.4), sodium sulfate (Na₂SO₄, 99.9%),
bovine serum albumin (BSA, 98%, molecular weight 68 kDa), and humic
acid (HA, >90%) were obtained from J&K Scientific Ltd. (China).
Except for the TMC organic solution, all solution preparations used
Milli-Q water as the solvent.

Bovine serum albumin (BSA, 98%), Araldite 506 epoxy resin and NOA86, which were purchased from J&K Scientific Ltd. (Beijing, China), Sigma-Aldrich (Shanghai, China), and Lienhe Fiber Optic Supplies (Beijing, China), respectively, were selected as the matrix material to create the high-quality resonators due to their outstanding flexibility. Glycerin (>99.5%) purchased from Alfa Aesar (Shanghai, China) was used to adjust the viscosity of the BSA aqueous solution, which is a key factor in preventing shrinkage of the printed structures after solvent evaporation. The materials were used as received without further treatment, unless stated otherwise.

Doxorubicin hydrochloride (DOX·HCl) was purchased from Dalian Meilun Biotechnology Co., Ltd. Bovine serum albumin (BSA) was purchased from J&K Scientific Ltd. GNRs, PNIPAM, and PEG-PLA were previously synthesized by our colleagues. Human melanoma cells B16F10 were purchased from the American Type Culture Collection. Dulbecco's Modified Eagle's Medium (DMEM) and fetal bovine serum (FBS) were purchased from Gibco Co, United States. The Cell Counting Kit-8 was purchased from Dojindo Laboratories (Kumamoto, Japan). The apparatus mainly consisted of a UV-VIS spectrophotometer (Cary300, Varian, CA, United States), a freeze dryer (VirTis AdVantage, United States), a dynamic light-scattering device (DLS, ALV/CGS-3, Germany), an infrared light source (IRS-S6, Shanghai, China), a transmission electron microscope (TEM) (Hitachi, H-7000 Electron Microscope), an inverted fluorescence microscope (Olympus IX71, Japan), and an enzyme-labeling instrument (Power Wave XS, Bio-TEK, United States).